Abstract: Dam leakage is a serious threat to the structural safety of dam. GPR (Ground Penetrating Radar) technology has such shortcomings as low depth of detection and low precision caused by electromagnetic wave attenuation in the safety detection of dam structure. In view of this, we propose a combined antenna technology with enhanced low frequency and antenna center frequency at 50 MHz. Dual-transmitter and dual-receiver design is employed to improve the antenna’s emission efficiency and enhance the capability of GPR’s deep detection. We further apply this technology to the leakage detection experiments for the dam of the South-North Water Transfer Project. Results demonstrate that compared with conventional radar antenna, the proposed enhanced low-frequency antenna effectively enhances the deep detection capability and effectively detect the abnormal target within 25 m depth in large moisture content environment, thus achieving the detection of water-rich areas and leakage channel. This technology provides data support for the safe management of dams.

Key words: GPR, dam body, leakage detection, dual-transmitter and dual-receiver, deep detection, South-to-North Water Transfer Project